Electrical distribution system



Oct. 28, 1930. w s, MOQDY 1,780,032

ELECTRICAL DISTRIBUTION SYSTEM Filed Dec. 18, 1929 Inventor: Walter S. Moodg,

Iatented Oct. 28, 1930 UNITEE STATES PATENT OFFICE WALTER S. MOODY, F PITTSFIELD, MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK ELECTRICAL DISTRIBUTION SYSTEM Application filed December 18, 1929. Serial No. 415,033.

My invention relates to electrical distribution systems and particularly to the automatic operation of transformer ratio adjusters under load in feeder regulating systems.

Ratio adjusters for transformers which are designed and constructed to operate under load involve apparatus of considerable complexity, which is not adapted for frequent and rapid movement. Automatic control of such devices as through their direct control by voltage responsive contact making means is consequently impractical. I, however, provide means in connection with a distribution system containing a plurality of feeders, with 5 their respective voltage regulators, for securing an additional range of voltage control through the automatic operation of a ratio adj uster on the supply transformer, such opera tion nevertheless being at time intervals so in- 0 frequent as to be unobjectionable.

It is an object of my invention to provlde a new and improved regulating system for dis tribution systems.

It is a further object of my invention to provide new and improved means for the automatic operation of a transformer ratlo adjuster under load conditions.

My invention will be better understood from the following description taken in connection with the accompanying drawing, and its scope will be pointed out in the appended claims.

Referring now to the single figure of the drawing, which is a diagrammatic representation of my invention, 1 is a supply transformer, whose primary winding 2 is connected to any suitable source of current supply 1 and whose secondary winding 3 is connected to bus 4 through a ratio adjuster 5, shown as of the tap changing type. This adjuster comprises a segmental arrangement of contacts 6, each of which is connected to a different tap 7 of the secondary 3. Arranged to move over these contacts is a brush arm 8 comprising a pair of relatively insulated brushes 9 connect- 25 are connected to the other field winding 26 ed to arm 8 through reactances 10. The purpose of this arrangement is to permit of changing from tap to tap without breaking the circuit or short-circuiting a portion of the secondary 3. Such arrangements are old and well known in the art. Connected to bus 4 d are a plurality of feeders 11, each with its separate regulator 12, illustrated as of the well-known induction type. Each regulator is provided with suitable means for securing its automatic operation comprising a voltage responsive contact making device 13, shown as a solenoid 1 connected across its respective feeder 11 for causing the operation of a suitable'switching device 15 for closing the circuit of one or the other of reversing field windings 16 on motor 17 The armature 18 of motor 17 is mechanically coupled to shaft 19 of each regulator through suitable gear mechanism 20. Each feeder voltage regulator is also equipped wit-h limit switching means shown as comprising a pivotally mounted contact arm 21, operatively connected to shaft 19 through suitable motion transmitting means 22, this arm being adapted to bridge contacts 23 and 24; when the regulator is in one of its extreme positions and to bridge contacts 24 and 25 when it is in its other extreme position. All of contacts 23 are connected to one field winding 26, of motor 27, while all of contacts of motor 27, which is arranged so as to cause reverse operation of the motor. Motor 27 is mechanically coupled to tap changing arm 8 by means of suitable mechanism 28. Contacts 24 are connected, through any suitable source i of current supply, shown as battery 29, to the other terminal of motor 27.

The operation of my device is as follows. Assume that each'of the feeders 11 is connected to avariable load and that power is being supplied to bus 4 through transformer 1. If the loads on feeders 11 are at or near their normal Values, regulators 12 will be at positions intermediate their extreme positions. Hence contacts 21 will be approximately midway between contacts 23 and 24. If now slight changes in load Occur on feeders 11, their respective regulators 12 will automatically regulate the voltage, through the operation of voltage responsive devices 13, causing motors 17 to turn their respective regulators in the proper direction. Consequently changes in voltage on feeders 11, within the range of regulation of regulators 12 will not causecontacts 21 to engage either contact 23 or contact 25 and hence will not cause the operation of motor 27 and ratio-adjuster 5. If, however, the voltage on any one or more of the feeders'll' should change beyond the regulating limits of its respective regulator, contact arm 21 will be made to bridge either contacts 23 and 24 or 24 and 25, thereby closing a circuit 'in-' cluding'motor 27 and the proper field winding thereof for causing its'rotation to be such as to make ratio adjuster 8 operate to produce such a voltage on bus 4 that the feeder regulator or regulators which are at,

their limits of regulation'will again be able to take up an intermediate position. When this happens, the circuit to motor 27 will be broken and the ratio adjuster will cease to operate until such time when any one of the feeder regulators, reaches the limit of its range. c 1

Althoug1'thefeeder regulators have been shown and described asvoltageregulators,

itwill of course be obvious to those skilled in the art that they couldequally well be current regulators without departing from myinventi'on. 7

H While I have shown and described aparticularembodiment ofmy invention, i t will be obvious to thOsefsk-illed in the art that changes and modifications ,may be made without departing from my invention and I, therefore, aim in the appended claims to.

cover all-suchchanges and. modifications as fall within the truespirit' and scope of my invention.

'What Iclaim as newand desiretosecure by g V 4 transformer, a plurality of feeder circuits,

Letters Patent of the United States, is,

- 1. In a system ofdistribution, a circuit,

a regulator therefor, said regulator having twoextreme positions which limit its range of regulation, an additional regulator for'said circuit, and means responsive tothe movement of said first-mentioned r regulator to either one ofits extreme positionsfor causing the operation of said additional regulator.

2. In a system ofdistribution,a plurality of feeder circuits, adjustable'mea-ns for varying an electrical characteristic of said 'cir cults, a separate regulatorihaving two predetermined regulating limitsfor each of said feeder circuits, and means cooperating with" saidadjustable meansfor effecting operation thereof when any one of said reg lat rs'aa mam of their respective feeders, and means oper ative in response to any one of said regulators reaching itslimit of regulation for causing said adjustable means to vary said characteristic in such manner that said regulator twill again operate within'its regulating range. 7

4. In a system of distribution, a source of current, a plurality of" feeder circuits, means connecting said source to said feeder circuits,

said means including adjustable means for varylng the voltage ofsaid feeder c1rcuits,va

separate voltage ,regulator for each feeder circuit, and means responsive to anyone off said regulators reaching its extreme 'regula't-f' ing position for causing said adjustable means to vary said voltage in such a manner that said regulator canoperate i'vitnin its regulating rangeQ V V v 5; In a system of distribution, a source of current, a plurality of feeder circuits,

means connecting'said' source to said feeder circuit, said l1182JlS .l Z1CluCl11lg adjustable;

means for varying an electrical characteristic of said feeder circuits, a separate voltage reg ulatorfor each feeder circuit, separate means responsive to variations in the voltage of each feedercircuit for causing. operation of its respective"regulator, and means respon sive to an extreme position Ofany' one of said a regulators for lcausi j 4 v, 7 able means to vary said voltage such 'a manner as to cause said regulator to leave its extreme position and for arresting the operation of said adjustable means when saidregulator leaves its extreme position; I l

,7 6. In a system of of alternating current, a transformer, means connecting said sourceto'one winding ofsaid' responsive tothe movement of; any one of said regulatorsto an extreme position for causing said ratio adj uster to operate in such a manner as to necessitate said regulator leaving its extreme position in order to perform 7 its regulating function; o 'Z'. In avsysteni'of alternating curre1 t,,jatransformer, means connecting the primary winding of said distribution, a sourcef' listribution, a s'ourcef of r i'is transformer, to said I source, a; plurality of feeder circuits, means connecting sai'd feeder circuits, to the secon'dary wind ng of said transformer, ratioad uster connected to said transformer, a separate regulator for each feeder, responsive to the voltage of its respective feeder, limit switches mechanically connected to each regulator, and means responsive to the closure of any one of said switches for operating said ratio adjuster in such a manner that the resultant voltage change on said feeders tends to cause the regulator, one of whose limit switches is closed, to open said switch.

In witness whereof, I have hereunto set my hand this 16th day of Dec, 1929.

WALTER S. MOODY. 

